The structure of [7,8-C2B9H12]–; correction of a popular misconception
- 1 January 1990
- journal article
- Published by Royal Society of Chemistry (RSC) in J. Chem. Soc., Dalton Trans.
- No. 2,p. 677-680
- https://doi.org/10.1039/dt9900000677
Abstract
The [7,8-C2B9H12]– ion has been shown, via n.m.r. spectroscopic and X-ray crystallographic study, to contain an endo-H atom bonded to B(10) and not, as generally thought, a B–H–B bridge. Four ion pairs of [H(dmso)2][C2B9H12](dmso = dimethyl sulphoxide) crystallise in a unit cell of dimensions a= 8.2919(14), b= 11.0802(21), c= 18.128(5)Å, β= 100.135(18)°, and space group P21/n. The structure has been refined to R= 0.0436, R′= 0.0698 for 2 355 reflections measured at 185 ± 1 K. The presence of an endo-H atom in [7,8-C2B9H12]– is rationalised by consideration of the form of the highest occupied molecular orbital of [7,8-C2B9H11]2–. Analysis of the results of extended-Hückel molecular orbital calculations confirms that the endo-H atom bonds to the cage via a four-centre two-electron bond, and allows the relative magnitudes of endo and exo B–H coupling constants to be understood as well as the observation of weak coupling between the endo-H atom and B(9) and B(11).Keywords
This publication has 18 references indexed in Scilit:
- Preface to ‘Comprehensive Organometallic Chemistry’Published by Elsevier ,1995
- Synthesis of the new boron hydride nido-undecaborane(15), B11H15, and the x-ray structure of its conjugate base tetradecahydroundecaborate(1-), [B11H14]-Inorganic Chemistry, 1988
- Synthesis and structural characterization of the first seven-vertex nido-carborane anion: nido-3,4-Et2C2B5H6-Organometallics, 1988
- Studies of 2,5;6,10;8,10-tri-µ-hydro-nonahydro-nido-nonaborate(1–), [B9H12]–: preparation, crystal and molecular structure, nuclear magnetic resonance spectra, electrochemistry, and reactionsJ. Chem. Soc., Dalton Trans., 1985
- Structural and Bonding Patterns in Cluster ChemistryPublished by Elsevier ,1976
- Coordination Number Pattern Recognition Theory of Carborane StructuresPublished by Elsevier ,1976
- Preparation and characterization of the (3)-1,2- and (3)-1,7-dicarbadodecahydroundecaborate(-1) ionsJournal of the American Chemical Society, 1968
- .pi.-Dicarbollyl derivatives of the transition metals. Metallocene analogsJournal of the American Chemical Society, 1968
- Carbametallic Boron Hydride Derivatives. I. Apparent Analogs of Ferrocene and Ferricinium IonJournal of the American Chemical Society, 1965
- Dicarbaundecaborane(13) and DerivativesJournal of the American Chemical Society, 1964